Have one person stand at the whistle post—off railroad property of course you don’t want to be a “terrible trespasser”
Have a second person stand at the crossing. When the train gets even with the whistle post take a cell phone hit the preset dial # of the persons cell phone standing at the crossing.
“Can you hear me now?” Dang I think I just invented the post mounted whistles that the tax-payers are paying like $40,000 a crossing for.